Netherportal doesn't work on Old worlds

I can't make a Netherportal in old worlds. The fire stays in the portal and nothing happens (See screenshot) I tried everything, Build it on another place or remove the corner blocks.

I can make it Infinite but i don't want, I like the world now.

McVersion: 0.12.1
WorldVersion: Old (No Infinite)
Device: Samsung Galaxy S4 Mini